STAP cells: Haruko Obokata agrees to retract controversial papers

The sordid tale of Haruko Obokata, a 30-year-old Japanese stem cell researcher at the Riken Center for Developmental Biology in Kobe, is fast coming to an end. Dr. Obokata shot to international prominence and became an overnight celebrity in Japan after the publication of her two “landmark” papers in Nature on January 30 this year.

On June 4, Dr. Obokata finally agreed to retract the second controversial paper, which details the fundamental mechanism of her research, a week after she agreed to retract the first one. Incidentally, the first retracted paper was not the one where image manipulation was spotted. “We are confirming that she has agreed to retract both articles,” a spokeswoman for the Riken Institute was quoted as saying in the Japan Daily Press.

A paper can be retracted (permanently withdrawn from the journal) only when all the authors agree to it. Dr. Obokata and another author based in Harvard were against such a move as they stood by their results.

But even as she retracted the papers, Dr. Obokato told her lawyer that retracting the papers “does not disprove her findings.” Ever since the controversy erupted less than three weeks after the publication of the papers, she has been steadfastly maintaining her claim to the validity of her research.

The “breakthrough” research was about a new way of reversing adult cells into pluripotent stem cells using slightly acidic conditions as a stressor. Besides the simplicity of the methodology, the stimulus-triggered acquisition pluripotency (STAP) cells so produced were projected to be better than even embryonic stem cells. While embryonic stem cells can form only embryonic tissue, the STAP cells had the ability to form both embryonic and placental tissues, the authors claimed.

But what is it that made her change her mind to retract the second paper as well within a short span of a week? On June 3, the Japanese media reported that genetic tests on 20 stem cell lines, including those reported in the papers did not match the mouse from which the adult cells were taken.

The lack of match questioned the fundamental issue of the STAP cells’ authenticity. The genetic test on 20 stem cell lines was a follow up of a preliminary study undertaken by one of the authors who did not see a match.

Meanwhile, according to a June 3 Nature blog post, Prof. Charles Vacanti, a senior co-author from Harvard University, who resolutely stood by the study results requested the journal to retract the paper. A Nature news item indicated that Prof. Vacanti’s request “came out of the blue.”

Journal’s role

But going by a report in The Asahi Shimbun, Prof. Vacanti and Dr. Obokata were just heeding a recommendation by the journal editors to retract the paper. “He apparently did so to protect his reputation and avoid being forced by Nature to retract the article,” the paper reported. “Lawyer Hideo Miki, who represents Obokata, said his client was told by Dr. Vacanti that withdrawing the paper seemed to offer the best option.”

What started as a case of plagiarism and duplication/manipulation of images and the inability of others to replicate the study findings had within a few months snowballed into a bigger controversy. The first jolt came when plagiarism and the use of the same image found in the paper were spotted in her doctoral thesis. Then came RIKEN Centre’s verdict — Dr. Obokata was found guilty of misconduct. The lack of genetic match only reaffirmed RIKEN’s verdict.

More trouble

The latest controversy is about the irregularities in her research proposal submitted when she applied for her current position at RIKEN and the manner in which she was hired, notes Japan Times. Besides others, the proposal had plagiarised text and the use of the same image found in the paper